Darwin's frog, found in the forest streams of Argentina and Chile, has quite possibly the weirdest birthing method of any creature. Instead of hanging out in ponds, these little tadpoles help give new meaning to fathers with big fat mouths.

This particular species, which is officially listed as vulnerable, is part of the genus Rhinoderma, which is the only one on the planet whose species raise their young like this. In fact, Darwin's frog may be the last member left - it's currently unknown whether the other member of its genus, the Chile Darwin's frog, has gone extinct or is still out there somewhere. The species get there name, unsurprisingly enough, from Charles Darwin, who first discovered the species during his voyage on the Beagle.

Conservationist Danté Fenolio explains just what how this particular brand of child-rearing works:

"They have a small opening below their tongue. After [the eggs] hatch, he takes the tadpoles into his mouth and manipulates them through that opening and into his vocal sac. For about 60 days, they go all the way through to development inside his vocal sac. At that point when they are ready, fully developed, he coughs up fully formed miniatures of the adult."

The frogs are tiny, generally only about an inch long. And while the species isn't technically endangered, it's in a precarious position, particularly since the Chilean government is considering placing hydroelectric dams in the vicinity of one of its key habitats. The species also has to worry about existing industrial development in its ecosystem, as well as the arrival of the chyrtrid fungus, which has wiped out amphibian species all over the planet.

That's why Fenolio has created what's known as an assurance colony, which is a population of the frogs bred in captivity under controlled conditions. This will help bolster the species's numbers, and the hope is to eventually introduce these frogs to the wild. As Fenolio explains:

"It is a very complicated conservation landscape. An assurance colony doesn't fix the problem in the wild. What you are trying to do is buy yourself some time."